Overexpression of HO-1 Contributes to Sepsis-Induced Immunosuppression by Modulating the Th1/Th2 Balance and Regulatory T-Cell Function
Background. Countervailing anti-inflammatory response and immunosuppression can cause death in late sepsis. Depletion and dysfunction of T cells are critical for developing sepsis-induced immunosuppression. Heme oxygenase-1 (HO-1) has a regulatory effect on differentiation and function of T cells an...
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Published in | The Journal of infectious diseases Vol. 215; no. 10; pp. 1608 - 1618 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
US
Oxford University Press
15.05.2017
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Subjects | |
Online Access | Get full text |
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Summary: | Background. Countervailing anti-inflammatory response and immunosuppression can cause death in late sepsis. Depletion and dysfunction of T cells are critical for developing sepsis-induced immunosuppression. Heme oxygenase-1 (HO-1) has a regulatory effect on differentiation and function of T cells and anti-inflammatory properties. We therefore investigated the immunosuppressive role of HO-1 in sepsis with a focus on its effects on helper T-cell (Th) differentiation and regulatory T cells (Treg). Methods. Sepsis was induced by cecal ligation and puncture (CLP). Mice were intraperitoneally injected with zinc protoporphyrin (ZnPP; 25 mg/kg), an HO-1 inhibitor, or hemin (20 mg/kg), an HO-1 inducer, at 24 and 36 hours post-CLP. Splenocytes were isolated 48 hours post-CLP. Mice were intranasally infected with Pseudomonas aeruginosa 4 days post-CLP as a secondary pneumonia infection model. Results. ZnPP improved survival and bacterial clearance, whereas hemin had the opposite effect in septic mice. CLP induced lymphocyte apoptosis and a proinflammatory Th1 to anti-inflammatory Th2 shift, which was attenuated by ZnPP. ZnPP attenuated the CLP-induced Treg population and protein expression of inhibitory costimulatory molecules. Furthermore, ZnPP improved survival in the secondary pneumonia infection model. Conclusions. Our findings suggest that HO-1 overexpression contributes to sepsis-induced immunosuppression during late phase sepsis by promoting Th2 polarization and Treg function. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Correction/Retraction-3 |
ISSN: | 0022-1899 1537-6613 |
DOI: | 10.1093/infdis/jix142 |